Genetics worksheet with answers

Free printable Genetics worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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Name: ____________________   Date: ____________

1.Easy
♂ Aa♀ AaAaaA

Two Aa parents are crossed. A gives tall plants and is dominant over a, which gives short plants. Click the cell for an offspring that has tall plants and is homozygous.

Aa × Aa
  1. 1a × A
  2. 2a × a
  3. 3A × A
  4. 4A × a
2.Easy
♂ Bb♀ BbBbbB

Two Bb parents are crossed. B gives black fur and is dominant over b, which gives white fur. Click the cell for an offspring that has black fur and is homozygous.

Bb × Bb
  1. 1b × B
  2. 2b × b
  3. 3B × B
  4. 4B × b
3.Medium
♂♀YXB​Xb​XB​

red-green colour blindness is X-linked recessive (allele b). A carrier mother, XBXb, has children with an unaffected father, XBY. The mother's gametes run down the side. Click the cell for an unaffected son.

♀ XBXb♂ XBY
  1. 1Xb × Y
  2. 2Xb × XB
  3. 3XB × Y
  4. 4XB × XB
4.Medium
♂♀Xh​YXH​Xh​

haemophilia is X-linked recessive (allele h). A carrier mother, XHXh, has children with an affected father, XhY. The mother's gametes run down the side. Click the cell for a carrier daughter.

♀ XHXh♂ XhY
  1. 1XH × Xh
  2. 2XH × Y
  3. 3Xh × Xh
  4. 4Xh × Y
5.Hard
♂ AaBb♀ AaBbABaBAbabaBabAbAB

Two AaBb parents are crossed. Gene A gives yellow seeds (dominant) or green seeds; gene B gives purple flowers (dominant) or white flowers. Click the one cell for an offspring that is homozygous for yellow seeds and for purple flowers.

AaBb × AaBb
  1. 1aB × AB
  2. 2aB × aB
  3. 3aB × Ab
  4. 4aB × ab
  5. 5ab × AB
  6. 6ab × aB
  7. 7ab × Ab
  8. 8ab × ab
  9. 9Ab × AB
  10. 10Ab × aB
  11. 11Ab × Ab
  12. 12Ab × ab
  13. 13AB × AB
  14. 14AB × aB
  15. 15AB × Ab
  16. 16AB × ab
6.Hard
♂ AaBb♀ AaBbAbaBABabABabAbaB

Two AaBb parents are crossed. Gene A gives yellow seeds (dominant) or green seeds; gene B gives round seeds (dominant) or wrinkled seeds. Click the one cell for an offspring that is shows both green seeds and wrinkled seeds.

AaBb × AaBb
  1. 1AB × Ab
  2. 2AB × aB
  3. 3AB × AB
  4. 4AB × ab
  5. 5ab × Ab
  6. 6ab × aB
  7. 7ab × AB
  8. 8ab × ab
  9. 9Ab × Ab
  10. 10Ab × aB
  11. 11Ab × AB
  12. 12Ab × ab
  13. 13aB × Ab
  14. 14aB × aB
  15. 15aB × AB
  16. 16aB × ab

Answer key

  1. 1. A × A
  2. 2. B × B
  3. 3. XB × Y
  4. 4. XH × Xh
  5. 5. AB × AB
  6. 6. ab × ab

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